1. Field of the Invention
The present invention generally relates to the field of computer input devices and, more particularly, to pointing devices, fingerprint acquisition devices, and secure fingerprint acquisition.
2. Background Description
Most common computer operating systems presently incorporate windowing in presenting information to users. Common examples of such software, often referred to as graphical user interfaces (GUIs), include Microsoft Corporation's Windows series and Apple Corporation's Mac OS. In such computer systems, a spatial metaphor is used to present information.
Some kind of pointing device is almost indispensable for the use of such a computer interface. Beginning with the mouse, a wide variety of pointing devices have been introduced, including trackballs, touchpads, and a variety of mechanical pointers. An example of such a pointing device is described in U.S. Pat. No. 5,489,900 to Cali et al. for “Force Sensitive Transducer for Use in a Computer Keyboard.”
Such pointing devices which are alternative to the mouse are especially desirable for use with mobile computers. The users of such mobile computers often do not have available the large, flat space necessary for operating the traditional mouse.
Hence, a flood of pointing devices has been introduced in recent years, adapted for use with mobile computers. Each such device has advantages and disadvantages, allowing for a range of alternatives which may be adapted to a variety of usage scenarios and personal preferences.
It would therefore be desirable to provide a fingerprint authentication device capable of allowing user pointing, which is compact enough for incorporation into a mobile computer or other portable electronic device. Such a device would allow for user authentication without separate, active intervention by the user.
U.S. Pat. No. 6,400,836 to Senior employs the steps of viewing the fingerprint as an elliptical region, using this view to find rotation in the plane of the scanner, and finding the principal axes of the region. However, it is has been found that when pressure is light, as when only the very tip of the finger is used, or when the finger is at the edge of the scanning area, the principal axis of the pixels does not correspond to the principal axis of the finger tip. As a result, the reliability of the scanning method disclosed in U.S. Pat. No. 6,400,836 could be improved.
Fingerprint matching is a well-established and reliable method of identifying individuals. As such, it provides a good method for authentication of the identity of a person for such purposes as enabling use of equipment, access to data, and the authorization of transactions. In recent years, powerful processors and new algorithms, coupled with a variety of new, “livescan” fingerprint scanning devices, have enabled the automatic verification of fingerprints on small computer platforms.
The incorporation of such authentication devices would be particularly useful for notebook, laptop and other mobile computers, as well as in other portable electronic devices such as cellular telephones, personal digital assistants, etc. Mobile computers are more likely than desktop computers to be present in unsecured areas where unauthorized individuals might attempt to use or access the computer. Because users of such mobile computers often have confidential or proprietary information stored in these computers, such users have a strong interest in maintaining the security of their computers. Similarly, mobile phones are carried in public and are easily stolen, presenting a considerable financial risk in unauthorized use.
Nevertheless, existing security systems for such computers and phones require intentional, active intervention by the user, such as entering passwords or using key locks. The inconvenience of such frequent activity, in conjunction with the user's fears of misplacing or forgetting the key or password, often result in users ignoring available security systems.
Biometrics systems that are not designed with the proper safeguards are vulnerable to a number of attacks which can bypass or invalidate the security derived from such a system. One such category of attack is the replay attach. In this situation, data captured at a previous verification session is recorded by an eavesdropper, and replayed to the system layer when claiming authorization. Such attacks can be prevented with this device in a number of ways.